Buprenorphine is a semisynthetic opiate used medicinally as a powerful analgesic, indicated for the treatment of moderate to severe pain and opioid dependence. The preparation of buprenorphine from thebaine is known and has been reported in publications to be carried out by the following 6 major step scheme:

The presently known method for preparing buprenorphine, however, has several drawbacks. The method is an unspecific reaction scheme, that is, the method produces many other unwanted products, i.e., impurities, along with the buprenorphine. Thus, the buprenorphine has to be isolated and purified, which is time consuming and inefficient.
Attempts have been made by others to improve the method of preparing buprenorphine. For example, U.S. Patent No. 2010/0087647 to Allen, which focuses on step 3 of the known process, i.e., Grignard reaction. This improvement retains the extraordinarily harsh conditions for removal of the methyl groups attached to the nitrogen and the phenolic oxygen and it therefore requires an additional purification step. Thus, there continues to be a need to improve the process of preparing buprenorphine that improves the yield of buprenorphine, and limits or reduces the number of impurities formed during the process.